Electric switch



T. C. FORBES ELECTRIC SWITCH Filed May 19 Jul 10, 1928.

In vent-oh Thomas C Rrbes.

fiti'orneys.

Patented July 10, 1 928.

UNITED STATES PAENT OFFICE.

THOMAS C. FORBES, OF HOPKINS, MINNESOTA, ASSIGNOR TO WATERS-GENTER COM- PANY, OF MINNEAPOLIS, MINNESOTA.

ELECTRIC SWITCH.

Application filed May 19.

and an ob ect is to provide a switch having fixed and movable contacts which are engaged and disengaged with a quick, snappy movement even when the initial operating means for the switch is moved very slowly. I accomplish the objects of my invention by providing a swinging switch arm which carries the movable contact and which has a dead-center in combination with a movable member, which, when it passes over the deadcenter in either direction, exerts a sudden thrust on the switch arm for opening or closing the switch accordin to the direction of movement of the movable member.

The full objects and advantages of my invention will appearin connection with the detailed description thereof, and the novel features of my inventive idea will be particularly pointed out in the claim.

In the accompanying drawingswhich illustrate one of the forms in which my invention may be embodied,-

Fig. 1 is a side elevational view of the switch in closed position. Fig. 2 is a similar view with small portions in section and showing the switch in open position. Fig. 3 is a front elevational view.

Referring to the construction shown in the drawings, the numeral 10 designates any suitable support upon which a fixed Contact is mounted. When the support is constructed of metal or other conducting material, the fixed Contact is insulatively mounted thereon. In the embodiment shown, this contact consists of a short, carbon cylinder 12 held in a split ring 14, the ends of which are held together by a screw 16 in order to clamp the ring on the cont-act.

An arm 18 extends from the ring-14 op-' posite the split therein and this 'armfis perforated for the passage of a bolt '20 which passes through a strip 22 of insulating material interposed between the support 10 and the contact 12 and through insulating material 24 extending through a hole in the support 10 so that the contact 12 and the bolt 20 are insulatively mounted. The bolt 20 is utilizedas a binding post for a wire 26 constituting one of the wires of an electrio circuit which is to be controlled. An

angular bracket 28 is insulated from the support 10 by insulating material 30 and is secured by bolts 32 arid 34 which pass through portions of the insulating material 1936. Serial No. 110,121.

placed in holes in the support. The bolt 34 serves as a binding post for the other wire 36 of the electric circuit. A switch arm '38 is pivotally mounted in the bracket 28 by a,pivot 40 passing through a circular marginal portion of the bracket and through a circular end portion of said arm. The other end of the arm 38 is made in the form of a split ring 42, the free end of which has a screw 44 passing therethrough in order that the ring may be clamped upon a carbon Contact 46 which is held from sliding backwardly in the ring by a lug 48 formed thereon. The intermediate portion of the switch arm 38 has a widened portion containing a V-shaped slot 50 which provides a shoulder 52 over which a roller 54 of fiber or other insulating material is adapted to run. This roller is grooved so as to be kept in engagement with the upper margin of the V-shaped slot and is mounted on a pin 56 secured to'the end of a bar 58 adapted to. bereciprocated or slid in any v in stressed engagement with the upper margin of the slot 50. In the. particular embodiment showinthe bar 58 may be reciprocated by a hand lever 64 pivotally attached thereto. This hand lever is intermediately pivoted to a fixed arm 66 which is shown as extending out from the bracket 28. It will be understood that the positioning of the handle 64 or other operating member ,will'depend upon the manner in which the support 10 is mounted and that for some purposes, it will be desirable to have the handle mounted in front of instead of at the rear of the support. Furthermore, the member which carries the fiber roller may be reciprocated in other ways as, for instance,

in the manner shown in the application for patent of Charles P. Strite for read toasters led July 10, 1926, SerialNumb'er 121,693."

If the switch 68 extending transversely from the a names? shown in Fig. 2 which causes the roller 5% tion, a pivot passing centrally through said I to run over the shoulder 52. As soon as the circular portions, a stop lug extending trans roller has passed the dead-center it exerts a versely from the periphery of the circular sudden thrust on the switch arm which reportion of said arm and adapted to engage sults in the switch being opened with a said bracket when said arm is in open poquick, snappy action. When it is desired to sition, said arm having an intermediate enclose the switch, the reverse action occurs. larged portion provided with a ii-shaped When the switch is in closed position, it is slot therein forming a shoulder, a contact obvious that current passes from a Wire 26 carried by the other end of said arm and to the engaged contacts 12 and 46, through adapted to engage said fixed contact, a fiber the switch arm 38 to the bracket 28 and out roller positioned in said slot, a bar on one through the wire 36. The direction of curend of which said roller is mounted, a lever rent may, of course, 'be in the reverse dito which the other end of said bar is pivoted rection according to the manner in which and by which said roller may be .moved the wires are connected with the source of across said shoulder, and 'a spring conelectrical energy. necting said bracket and said bar which I claim: causes said roller to exert a sudden thrust An electric switch comprising a support, on said switch arm when said roller passesa fixed contact'insulatively carried by said over said shoulder in either direction.

' support and havini support, a bracket insulativelysecured to said In testimony whereofl hereunto aflix my a circular marginal porsignature. tion, a switch arm aving a circular end por- THOS C. FORBES. 

